The present invention relates to the field of radiation protection for printed circuit board components and more particularly to an electromagnetic compatability (EMC) shield and housing for such components. The instant shield and housing provide for the possibility for many different component to operate within a substantially electromagnetic environment without degradation in individual performance and the like. Such degradation would otherwise have resulted from electromagnetic interference.
Shielding against electromagnetic radiation is becoming increasingly relevant for electronic apparatus as their sensitivity is becoming ever greater, their performance is increasing, and modern electronic components comprise ever higher clock rates. The EMC as defined in various Standards and works both to protect the electronic components against external electromagnetic radiation and reduce external effects of electromagnetic radiation produced by the shielded components. Exemplary fields of application in which EMC shields are used for electronic components include, electronic controllers for motor vehicle technology and communication terminals which operate in a radio-frequency band, e.g. mobile telephones.
A known example of forming an EMC shield for electronic components on a printed circuit board is to arrange the entire printed circuit board, together with the electronic components, within a housing which provides shielding against electromagnetic radiation. A shielding housing of this type is set out in German reference DE-A1-199 56 184. A disadvantage to this approach is that the provision of connections which have to be passed out of the shielding housing from the printed circuit board in an EMC-compliant manner requires that there be a lack of shielding between individual electronic components. In addition, shielding housing is rather large, heavy, and cumbersome.
In order to avoid these disadvantages, use is made of local EMC shields which are provided immediately around particular electronic components. Such shields are set out in German reference DE-A1-41 37 112. Local EMC shields four side walls and a cover. Side walls of the local shields are soldered to the printed circuit board. To do this, a solder deposit can be provided either on the EMC shield, as is described in German reference DE-C1-198 40 234, and/or on the printed circuit board. Alternatively, the side walls of the EMC shield may also have solder pins, which are passed trough appropriate holes in the printed circuit board and soldered on the boards rear face. These solutions have the disadvantages of the large number of solder points that are required and of the expensive and complex soldering facilities which are requited to solder them. In addition, in the last-mentioned case with plated-through holes, a restriction to the printed circuit board layout is present.